Work Flow

When cores access shared data:

• Read operation:
  • If a core reads data missing from L1, it will request from L2.
  • If another core has data in a modified state, that core must supply or write back the updated data.
  • L2 ensures all cores receive the correct (latest) value.
• Write operation:
  • If a core wants to write:
    • It must obtain exclusive ownership of the cache line.
    • Other cores’ copies are invalidated.
  • The writing core updates its local cache.
• Eviction:
  • If a line is evicted from L1, it is written back to L2.
  • If a line is evicted from L2, it is written back to the main memory.